Late reconstruction of two total metacarpal bone defects using lengthening devices and a double-barrel osteocutaneous free parascapular flap

A case was presented in which the late reconstruction of left ring and little metacarpal bone defects was carried out using a lengthening device and a double-barrel osteocutaneous free parascapular flap. With this flap, up to 14 cm of nearly straight bone of a suitable width and length for the reconstruction of two metacarpal bones was raised safely. However, it required 3 months of lengthening to create enough space to insert the grafted bone because of the severe resistance of scar contracture and fibrous tissues.     

Metacarpal synostosis: a simple classification and a new treatment technique

The current classification of metacarpal synostosis is based on the extent of the synostosis. The authors propose a new classification that takes into account the shape of the metacarpal bones, the curvature of the epiphysis, and the discrepancy in length between the two bones. This classification provides better guidelines for the correction of all components of the deformity. The classification is based on the authors' observations of and experience with 36 cases of metacarpal synostosis; 13 of the deformities were surgically corrected. The I-shaped deformity, whether with distinct (type d) or fused (type f) metacarpophalangeal joints, does not require surgical correction. The U-shaped deformity has parallel epiphysis and does not require surgery unless the two metacarpals are asymmetrical in length (type a) or tightly fused (type t); in these cases, simple lengthening or widening of the space with a bone graft is sufficient. Y-shaped synostosis should be separated whether the branches are symmetrical or asymmetrical, the latter having one branch shorter than the other. Because the epiphyses are already divergent, simple separation does not effectively correct Y-shaped synostosis. The authors propose an osteotomy to isolate a trapezoidal segment of bone from the bifurcation. The isolated bone segment is then reversed in the proximal-distal direction to provide a "plateau" upon which the two distal metacarpals can be realigned. Two cases of Ys (symmetrical) synostosis were successfully treated with this technique; one case of Ya (asymmetrical) synostosis also required distraction lengthening of the shorter metacarpal to achieve an excellent result. One of the most difficult types of metacarpal synostosis to treat is k-shaped synostosis, observed only between the fourth and fifth metacarpals; in this type, the head of the short fifth metacarpal abuts the metaphysis of the fourth. Osteotomy and distraction lengthening provide predictable results for correction of this deformity. The authors suggest that k-shaped synostosis might represent a late evolution of untreated Ua synostosis.     

Features of the structure of the metacarpal bones of athletes in different specialties

Metacarpal bones have been examined in hand X-ray photos of 125 sportsmen at the age of 17-18 years who go in for swimming (dynamic loading on the hand) and competitive gymnastics (static loading on the hand). Under the effect of systematic trainings, which are connected with an increased loading on the hand, a number of morphological changes take place in the metacarpal bones. A prolonged loading of the dynamic character delays the synostosis process in the distal parts of the forearm bones and contributes to lengthening the I, III and IV and to widening the I-V metacarpal bones. As demonstrate decreasing indices of compactness in the swimmers, the widening diaphisis of the metacarpal bones occurs at the expense of dilatation of the medullary cavity. The static loadings result in a greater delay of the synostosis processes in the upper extremity parts mentioned, in a greater width of the I-III, V metacarpal bones in boy-gymnasts. The increased index of compactness demonstrates that the widening diaphysis of the metacarpal bones takes place at the expense of thickening of the compact substance and narrowing of the medullary cavity.     

掌骨X线测量推断身高的研究

随机选取在校健康大学生186人(男90人, 女96人, 年龄18—27岁), 拍摄双手后前位372侧X线片, 测量身高和掌骨的长与宽。通过掌骨和身高的测量, 分析掌骨各参数与身高的关系, 为人类学和法医学的身高推断积累研究资料。掌骨长与身高的相关性明显高于掌骨宽, 其中男性第2掌骨长与身高相关性最高, 其线性回归方程为Ym=1097.320+9.337X; 女性第3掌骨长与身高的相关性最高, 其线性回归方程为Yf=1016.752+9.878X。男性第2掌骨长和女性第3掌骨长与身高的相关性最高, 可分别作为推断身高的依据。     

The boomerang flap in managing injuries of the dorsum of the distal phalanx

Finding an appropriate soft-tissue grafting material to close a wound located over the dorsum of a finger, especially the distal phalanx, can be a difficult task. The boomerang flap mobilized from the dorsum of the proximal phalanx of an adjacent digit can be useful when applied as an island pedicle skin flap. The vascular supply to the skin flap is derived from the retrograde perfusion of the dorsal digital artery. Mobilization and lengthening of the vascular pedicle are achieved by dividing the distal end of the dorsal metacarpal artery at the bifurcation and incorporating two adjacent dorsal digital arteries into one. The boomerang flap was used in seven individuals with injuries involving the dorsal aspect of the distal phalanx over the past year. Skin defects in all patients were combined with bone,joint, or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-step procedure preserves the proper palmar digital artery to the fingertip and has proven valuable for the coverage of wide and distal defects because it has the advantages of an extended skin paddle and a lengthened vascular pedicle. When conventional local flaps are inadequate, the boomerang flap should be considered for its reliability and low associated morbidity.     

Dislocated intra-articular fracture of the base of the fifth metacarpal: a clinical study of 23 patients

Twenty-three patients with dislocated intrarticular fractures of the base of the fifth metacarpal were treated during the last 3 years in our department. This fracture characteristically occurs in young, active males, and the most frequent mechanism of this injury is axial force striking the metacarpal head, mostly in fist fights. In 8 patients, the fracture was caused by direct force hitting the base of the fifth metacarpal. Four certain fracture patterns are described. Operative treatment by open reduction and fixation with two Kirschner wires generally gave good results.     

Comparative anatomical study of arteriographs of the hand of primates. Deep palmar arterial arches and their correlating arteries in cercopithecidae, pongidae and hominidae

A three-dimensional angiographic analysis of the deep palmar arterial arches and their correlating arteries in Cercopithecidae, Pongidae and Hominidae revealed the following features. In Cercopithecidae, 3 deep palmar arches are formed by the perforating branches of the 2nd dorsal metacarpal artery: 2 proximal arches (the catella volaris proximalis and the arcus volaris profundus) and 1 distal arch (the catella volaris distalis). The intermetacarpal arteries arise from the catella volaris proximalis and the palmar metacarpal arteries arise from the arcus volaris profundus. In Pongidae, the arches are formed by the perforating branches of the 1st dorsal metacarpal artery, and they are composed of only the catella volaris proximalis and catella volaris distalis. In Hominidae, the arches are formed by the perforating branches of the 1st dorsal metacarpal artery, and they consist of the arcus volaris profundus and an incomplete catella volaris distalis.     

基于有限元的第5 掌骨颈骨折钢板螺钉内固定的生物力学分析

目的：应用有限元方法建立三种不同的治疗第5 掌骨颈骨折的钢板螺钉内固定模型,比较三种模型的生物力学稳定性,为 第5 掌骨颈骨折的临床早期功能康复提供参考。方法：选取一名健康青年志愿者,将CT 扫描数据导入三维有限元软件建立第5 掌骨颈骨折模型,并选取三种钢板螺钉内固定方法进行骨折固定。对三种模型施加外力荷载并进行生物力学有限元分析,对比骨 折断端的最大位移和钢板螺钉的应力分布情况。结果：方法一、二、三的第5 掌骨骨折端的最大位移分别为0.189775 mm、 0.181428 mm、0.224299 mm,以方法二的骨折端位移最小;内固定材料的最大应力分别为1.20 KPa、1.00 KPa、1.39 KPa,以方法二 的钢板螺钉应力最小。结论：采用近端三颗螺钉远端两颗螺钉的直型钢板内固定方法治疗第五掌骨颈骨折的生物力学稳定性更 好,术后早期功能锻炼的安全性更高,是治疗第5 掌骨颈骨折的理想内固定方法。     

Ecological correlates and determinants in the geographical variation of deer morphology

Previous studies on patterns in ungulate size variations have emphasized the effect of a particular environmental factor such as Bergmann's rule and the island rule. However, although multiple environmental factors may influence the body size, these studies focused on a single factor, and various measurements that may be influenced by different environmental factors (at least partly) were used as indices of body size. In this study, we used several skull and limb measurements to examine size variations among island populations of sika deer (Cervus nippon) in southern Japan considering the effects of multiple environmental factors. We found that all measurements differed markedly between populations. We focused on the skull and limb condylobasal length (CBL) and metacarpal length because they had the most important variations among the populations and the largest sample sizes. The common environmental factors influencing CBL and metacarpal length were island area and precipitation. Since these environmental factors reflect the availability of food resources, the causal factor of body size variation may be food resources. Interpopulation variation in metacarpal length was greater than that of CBL, indicating that metacarpal length may be affected by additional factors besides the common factors shared with CBL. Specific environmental factors influencing relative (CBL adjusted) metacarpal length were precipitation and slope. A common direct cause of those environmental factors was discussed in relation to topography. Analyses of phenotypic variation using multiple measurements with multiple environmental factors are useful to gain insight into underlying causes and can lead to identification of a measurement-specific variation with a specific driving force.     

Growth and shaping of metacarpal and carpal cartilage anlagen: application of morphometry to the development of short and long bone. A study of human hand anlagen in the fetal period

A histological and morphometric analysis of human metacarpal and carpal anlagen between the 16th and 22nd embryonic weeks was carried out with the aim of studying the establishment of the respective anlage architecture. No differences in the pattern of growth were documented between the peripheral and central zones of the metacarpal epiphyses and those of the carpals. The regulation of longitudinal growth in long bone anlagen occurred in the transition zone between the epiphysis and the diaphysis (homologous to the metaphyseal growth plate cartilage in more advanced developmental stage of the bone). Comparative zonal analysis was conducted to assess the chondrocyte density, the mean chondrocyte lacunar area, the paired chondrocyte polarity in the orthogonal longitudinal and transverse planes, and the lacunar shape transformation in the metacarpal. In transition from epiphysis to diaphysis chondrocyte density decreased and mean lacunar area increased. No significant differences in the chondrocyte maturation cycle were observed between proximal/distal metacarpal epiphyses and the carpal anlagen. The number of paired chondrocyte oriented along the growth vector was significantly higher in both proximal/distal transition zones between epiphysis and diaphysis. Human metacarpals shared with experimental models (like mice and nonmammal tetrapods) an early common chondrocyte maturation cycle but with a different timing due to the slower embryonic and fetal developmental rate of human anlagen.     

Paradoxical bilateral asymmetry in bone size and bone mass in the hand

Among 227 chronic renal disease patients, micrometer caliper radiogrammetric measurements of the second metacarpal at midshaft showed the right metacarpal to be larger (with greater bone area) and with a greater cortical area than the left second metacarpal, both in 208 right-handed individuals and in 19 left-handed individuals. This direction of asymmetry was individually characteristic of the majority of individuals, whether right-handed, left-handed or ambidextrous.     

Osteocutaneous posterior interosseous flap for reconstruction of the metacarpal bone and soft-tissue defects in the hand

A vascularized bone segment of the ulna together with a posterior interosseous fasciocutaneous flap is harvested, including a cuff of the extensor pollicis longus muscle. The authors treated five male patients with metacarpal bone and soft-tissue defects of the hand using a distally based island osteocutaneous posterior interosseous flap. Their ages at the time of surgery ranged from 15 to 37 years (mean, 24 years). The bone defects were in the first metacarpal in three cases, the fourth metacarpal in one, and the fifth metacarpal in one. The length of the donated ulna ranged from 3 to 7 cm (mean, 5 cm). The follow-up period ranged from 5 to 92 months (mean, 39 months). All flaps survived completely. The posterior interosseous flap provides thin skin of good texture, together with vascularized bone, for a one-stage reconstruction of the metacarpal bone and soft-tissue defects in the hand.     

Study of arterial patterns of the hand in primates. Deep palmar arterial arches and their correlating arteries in Macaca fuscata

Study of the arterial patterns of the hand in Macaca fuscata, especially those of the deep palmar arterial arches and their correlating arteries, by three-dimensional arteriographic analysis revealed the following: (1) The deep palmar arterial arches are formed by the perforating branches of the 2nd dorsal metacarpal artery, and they are usually composed of two proximal arches (catella volaris proximalis and arcus volaris profundus) and one distal arch (catella volaris distalis). (2) In the 3rd and 4th metacarpal interosseous spaces, the intermetacarpal arteries arise from the catella volaris proximalis, and the arcus volaris profundus has palmar metacarpal arteries which descend along the palmar side of each metacarpal bone. (3) There is a definite regularity in the formation of the intermetacarpal arteries between the catella volaris proximalis and the catella volaris distalis and of the palmar metacarpal arteries between the arcus volaris profundus and the catella volaris distalis.     

Reconstruction of bilateral metacarpal hands with multiple-toe transplantations.

Bilateral metacarpal hands, if not treated properly, leave a patient without prehensile ability in both hands. Since 1990, six patients with bilateral metacarpal hands caused by accidents have undergone reconstruction with multiple-toe transplantations. Four or five toes were used for each patient, with a total of 27 toes transplanted to the hands. There was no toe loss. One nonunion in a middle-finger reconstruction was treated successfully with bone grafting. Secondary operations for functional improvement included one joint fusion and one flexor tendon tenolysis. Only one patient required excision of a plantar callus 42 months postoperatively, whereas the other five patients reported no major donor-site problems in an average 57 months of follow-up time. The six patients continue all their daily activities independently. Although their jobs were changed, all adult male patients were able to return to regular work. Principles of reconstruction to achieve satisfying prehensile function combined with minor donor-site morbidity in bilateral metacarpal hands include an adequate soft-tissue coverage before toe transplantations, selection of digits to be reconstructed based on functional and individual requirements, selection of toes and number of toes to be harvested based on consideration of usefulness for the hands and of foot morbidity, and consideration of thenar function in planning the sequence of transplantations. In conclusion, given thorough planning, multiple toe-to-hand transplantations can provide adequate prehensile function in reconstructed bilateral metacarpal hands with acceptable donor-site morbidity.     

The estimation of adult stature from metacarpal bone length

Stature was measured (in cm) in 166 (120 male; 46 female) predominantly white adults (age range: 17–87 years). A radiograph of one hand of each subject was taken (for routine diagnostic purposes) and the inter-articular length of all five metacarpal bones was measured with a sliding caliper. These metacarpal lengths were then adjusted to compensate for enlargement during radiography. A significant correlation coefficient between stature and metacarpal length was observed in both sexes. Regression equations were computed from the length of each metacarpal, by which living stature may be fairly accurately estimated in the absence of any complete limb bones. The difference between our estimates and those obtained by more orthodox methods is usually less than 3%.     

Extensor carpi radialis longus muscle and the evolution of the first intermetacarpal ligament

The morphology and function of tendinous connections between the bases of the first and second metacarpal bone was studied in dissected specimens. The sample comprises 28 hands from eight species of cercopithecidae and pongidae and 23 human hands. Four types were identified: (1) No intermetacarpal connections were present. (2) The extensor carpi radialis longus tendon was divided at the carpus and the side branch inserted on the ulnar side of the base of the first metacarpal bone. (3) Part of the fibers of the extensor carpi radialis longus bypassed the insertion on the second metacarpal bone and continued to the base of the first metacarpal bone. A few proper intermetacarpal fibers were included. (4) An extracapsular, intermetacarpal ligament was present. Its fibers were mainly separated from the extensor carpi radialis longus. Type 1 is a general mammalian form. Type 2 is common in higher, non-human primates. Type 3 was found in 2 of the 23 human hands and otherwise among the anthropoid apes only. Type 4 is apomorph in man. Individual variations exist though. Type 3 and especially type 4 could check ab- and adductions and guide a circumduction in the first carpometacarpal joint.     

The capitate of Australopithecus afarensis and A. africanus

The capitates of Australopithecus afarensis (AL 288-lw and AL 333–40) and A. africanus (TM 1526) have the identical combination of modern pongid, modern hominid, and unique characteristics. These traits include the combination of a length that is proximodistally shortened (Homo sapiens-like), a facet for the second metacarpal that is distolaterally facing (unique), the reduced styloid process on the third metacarpal (pongidlike), a dorsally placed trapezoid facet (pongidlike), mediolaterally constricted metacarpal III facet (pongidlike), a prominent palmar beak (pongidlike), a single elongated facet for the second metacarpal (H. sapiens-like), a waisted neck (pongidlike), and a reduced amount of “cupping” in the third metacarpal facet (H. sapiens-like). In overall shape the bones are more like H. sapiens than other extant hominids, although they are uniquely different. The two A. afarensis capitates provide no evidence that there are two postcranial morphotypes at Hadar. Available evidence shows that A. afarensis and A. africanus are strikingly similar postcranially. The morphological differences between the capitate of Australopithecus and H. sapiens may relate to the retention of climbing ability and an absence of certain grip capabilities in these early hominids.     

Chondromyxoid fibroma of the second metacarpal bone--a case report

This report describes a chondromyxoid fibroma of the second metacarpal bone in a 32-year-old female patient. Chondromyxoid fibroma is a rare, benign, slow-growing bone tumor of cartilaginous origin. Tumor has a high recurrance rate. Our aim was to show successful treatment of a metacarpal chondromyxoid fibroma with wide resection and implantation of finger join endoprosthesis.     

Ia-afferent input to motoneurons during shortening and lengthening muscle contractions in humans.

The central nervous system employs different strategies to execute specific motor tasks. Because afferent feedback during shortening and lengthening muscle contractions differs, the neural strategy underlying these tasks may be quite distinct. Cortical drive may be adjusted or afferent input regulated. The exact mechanisms are not clear. Here, we examine the control of synaptic transmission across the Ia synapse during shortening and lengthening muscle contractions. Subjects were instructed to maintain isolated activity in a single tibialis anterior (TA) motor unit while muscle length was varied from flexion to extension and back. At a fixed interval after a firing of the active motor unit, a single electrical stimulus was applied to the common peroneal nerve to activate Ia afferents from the TA muscle. We investigated the stimulus-induced change in firing probability of 19 individual low-threshold TA motor units during shortening and lengthening contractions. Any change in firing probability depends on both pre- and postsynaptic mechanisms. In this experiment, motoneuron firing rate was similar during both contraction types. There was no difference in the firing probability between shortening and lengthening contractions (0.23 +/- 0.03 and 0.20 +/- 0.02, respectively). We suggest that there is no contraction type-specific control of Ia input to the motoneurons during shortening and lengthening muscle contractions. Cortical adjustments may have occurred.     

Growth,slaughter and intra-muscular collagen characteristics in Garganica kids

Growth performance, ossification of metacarpal growth plate, and intra-muscular collagen characteristics in three muscles of 10 intact male Garganica kids were studied. Each week, starting from the 47th day of age to slaughter (75th day of age), kids were weighed and blood samples taken for plasma non-protein hydroxyproline analysis. At slaughter, metacarpal, metatarsal bones and metacarpal growth plate thickness were measured. The semitendinosus (ST), semimembranosus (SM), and rectus medialis (RM) muscle samples were analysed for collagen concentration and hydroxylysyl pyridinoline (HP) cross-links. ST muscle had a collagen amount higher than SM and RM (P<0.01), and RM muscle had the highest (P<0.01) HP concentration. Tenderness index was the highest (P<0.01) in RM muscle. Animal growth rates slowed, starting from 61st day of age (P<0.01); this trend coincided with a marked reduction in concentration of plasma non-protein hydroxyproline (P<0.01). In addition, plasma non-protein hydroxyproline concentration was positively correlated (r=0.61, P=0.001) with growth rate of animals, suggesting that collagen turnover decreases during a slow growth phase. Based on the metacarpal growth plate width, the rate of bone ossification appears to be slower in goats than sheep.